1. Field of the Invention
The invention relates to a method for forming images comprising providing a protective layer formed of thermoplastic resin particles over images formed on a recording medium and an apparatus for carrying out the method for forming images.
2. Related Background Art
In recent years, the progress of the ink-jet recording technique is noteworthy and its image quality has reached a level equal or superior to that of a silver halide print. As to recording media used for this ink-jet recording process, those with an image-receiving layer, containing porous particles excellent in absorbing and fixing recording liquid, provided on a base material such as paper are known.
Also known is, a laminating treatment of a recorded image by transferring and laminating a transfer layer comprising a thermofusing resin layer provided on a base material onto a recorded image by heat and pressure adhesion to give waterproof, light resistance, glossiness, etc. By having a UV absorbing agent contained in the transfer layer during this treatment, it is also possible to provide a sufficient light resistance to a print. Furthermore, by devising the material and constitution of this transfer layer, many laminating treatments of an image for simply and easily providing the wear resistance, solvent resistance, or the like by use of a resin have been worked out thus far.
FIGS. 6A to 6C are schematic sectional views of a conventional laminating method. The film with a base material shown in FIG. 6A basically comprises a transfer layer 1 to be transferred and laminated onto the surface of a recorded image and a base material film 2 for bearing the transfer layer 1. The transfer layer 1 can be peeled off from the base material 2 so as to be transferred and laminated to the image-receiving layer of a recording medium after recording.
As shown in FIG. 6B, the transfer layer 1 is laminated while remaining borne on the base material film 2 so as to directly cover the top of the image-receiving layer 3a on an ink-jet image-receiving paper 3 after recording and applied onto the image-receiving layer 3a by pressurization and/or fusion.
As shown in FIG. 6C, the base material layer 2 is peeled off from the transfer layer 1 after the transfer layer is applied onto the recorded image, and the transfer layer 1 alone is left as a protective layer on the image receiving layer 3a. 
The principal problem of the construction comprising a transfer layer 1 and a base material film 2, as shown in FIGS. 6A, 6B and 6C, is the high cost. In a laminating treatment as mentioned above, a base material film comprising a heat resistant material is necessary for the base material film 2 on which a resin layer to be transferred by heat and pressure adhesion on the recorded side is formed. In this film, not only heat resistance but flatness sufficient for giving the glossiness of a protective film after the transfer is also required, thus resulting in high cost. The cost of this base material film 2 has a much greater weight than that of a transfer material remaining as the final product or that of coating of a transfer layer. Sufficiently stable and deformation-free raw materials of a protective layer under conditions assumed for the thermal transfer include PET film, polyamide film, polyimide film and so on with thermal shrinkage controlled by preannealing, but any of them is a high-cost material. With such a constitution, a wide variety of applications truly low in cost and highly general in purposiveness are difficult to create.
The second problem of this constitution lies in that the base material film 2 becomes a used waste. From the viewpoint of processing cost, coating of a transfer layer 1 is ordinarily executed on a wide roll before slitting. Thus, recycling of used base material films 2 cannot be directly performed. Supposing that used basic films 2 are recycled, they would be done on the level of raw materials. Thus, it costs labor to collect and recycle them. Besides, a mechanism for rewinding a film after the image transfer in an apparatus, a space for disposing the mechanism, a power source for moving the mechanism or control system and so on are necessary. In a case where a laminate material has been cut, winding is unnecessary, but a mechanism for carrying used basic films 2 and accumulating them in a predetermined space is still necessary.
The third problem of this constitution lies in that the function of a protective layer transferred and formed varies with physical property, surface property, thickness or the like of base material films 2. This especially affects the glossiness, the adhesion of a film and the bubble releasability to a great extent. Originally, the transfer process of a glossy protective layer is a complicated process in which many parameters are involved, so that addition of such an influential variable factor is unfavorable to the stability of phenomena.
On the other hand, in Japanese Patent Application Laid-open No. 5-232841, a way to prepare a glossy sheet by using a transparent toner is described. Furthermore, in this specification, a way to make a record after preparing the glossy sheet by using the transparent toner is described. Since a record is made on the transparent toner, compatibility between the transparent toner and the ink must be considered.
It is one object of the present invention to provide an image forming process and an image forming apparatus capable of solving the problems mentioned above and forming an image good in glossiness at low cost and free of used wastes.
A process for forming images according to the present invention includes the steps of conducting recording on a recording medium provided with an image-receiving layer, providing thermoplastic resin particles onto the image-receiving layer, and heating and pressurizing the thermoplastic resin particles on the image-receiving layer.
Besides, an apparatus for forming images includes an ink-jet head for conducting recording on a recording medium, providing means for providing thermoplastic particles to the recording medium on which recording has been conducted, and heating and pressurizing means for heating and pressurizing the thermoplastic particles to flatten.